System of synchronizing signaling apparatus



Feb. 28., 1928.

A. L. MATTE SYSTEM OF SYNCHRONIZING SIGNALING APPARATUS Original Filed Feb. 26, 1925 iZ'awt" INVENTOR.

zmmm BY W 6 ATTORNEY apparatus at points Patented Feb. 28, .9.28.

UNITED. STATES PATT OFFICE.

ANDREW L. MATTE, OF SUMMIT, NEW JERSEY, ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

sYs'rnm QF synonnonrzrne sIGnALIne APPARATUS.

Driginal application filed February 26,

An object of my invention is to provide a new and improved s stem of synchronizing between which an electrical transmission is'efiected. Another oh- 5 ject of my. invention is to provide for proper ,synchronous'relation ofthe currents in the various parts of an electric signaling system. Another object is to provide for synchronizing by currents of suitable frequency, more particularly to synchronize relatively low frequency apparatus by transmission of higher frequency currents. Still another object is to governthe frequency of a vacuum tube oscillator by impressing a current of harmonic frequency thereon. These and various other objects of my invention will become apparent on consideration of an embodiment of the invention which I have chosen for illustration and which I now presentby way of example in the following specification taken with the accompanaying drawing. It will be understood that the invention is defined in. the appended claims and that the following description relates more particularly to the example'shown in the drawing.

The drawing is a diagram of a' two-way signaling system in which my. invention may be practiced advantageously. For convenience the apparatus at the two ends of this system are designated, respectively, as west and east.

At station west a plurality of vacuum tube oscillators such as 48, 48 and 48" are coupled successively through the resistances such as 49 and 4 These oscillators are adjusted as nearly as practicable so that the natural frequency of one of them is a certain comparatively low frequency fundamental, and the others are harmonics thereoef. By virtue of the couplings through the resistances such as 49' and 49 the battery of oscillators are forced so that they operate precisely at the harmonic frequencies just mentioned and which would be realized only approximately if the oscillatorshad no connection with one another.

The various voltages from the various oscillators are taken ofi across the resistances such as 49, 49' and 4 and thecondensers 95, etc. These are respectively in quarter phase relation, and each pair of quarter phase voltages are impressed upon the grids f two push-pull vacuum tubes which, pre- 1925, Serial No. 11,801. Divided "and this application filed May 24, 1927. Serial No. 193,895.

senting a substantially infinite impedance to and then transmitted through sending filters which are common toboth phases and thence superposed in the common line W The output currents in quarter phase relation are also available over branch circuits and 31 as a supply for reception of the incoming signals received over line W Inductances 96, etc., each in series with a resistance 49 and a condenser 95 above referred to, are adjusted to neutralize the negative reactance of the plate filament circuit. The resistances such as 92, 94.- are very large. They serve to maintain a high voltage across the oscillating circuits such as 93.

- One harmonic voltage, as from the oscillator 48 is taken off across the resistance 49", and after passing through the filter SF is put on the line without having any message signals impressed thereon.

At the station east this last mentioned particular harmonic frequency goes over the conductor pair through an appropriate and filter BF to the transformer prlmary The battery of oscillators such as 50, 50' and 50" are adjusted as nearly as practicable to have the same natual frequencies as the re spective oscillators at the station west such as 48, 48' and 48". One of these oscillators 50" is adjusted-to have as nearly as practicable the same frequency as the oscillator &8' from which the pilot frequenc for synchronizing purposes was "drawn. The input circuit of the oscillator 50" comprises a coil 52 Whichis made the secondary to the primary winding 53 already mentioned. Thus the synchronizing frequency transmitted over' the line W is applied to the oscillator 50" and forces it to operateprecisely at that frequency. Then by virtue of the r esistance couplings between successive oscillators such as 51 and 51 the whole battery of oscillators at station east is forced to operate at the same respective frequencies as for the oscillators at station west.

The output circuits from the respective oscillators 50,50, etc., go through filters and "harmonic frequencies and coupling these os I 1925, and renewed on or shortly before the date of filing the present application.

I claim:

1'. The method of producing a plurality of alternating currents in harmonic relation to one another, which consists in generating them respectively in vacuum tube oscillators adjusted approximately to the respective cillators together whereby they are forced to operate atthe precise harmonic relations.

2. In combination, a plurality of vacuum tube oscillators adjusted approximately to respective frequencies harmonic to a certain fundamental, and means coupling theseoscillators whereby they are forced to operate at precisely the harmonic frequencies to which they are approximately adjusted.

3. The method of signaling which comprises generating at the sending end a plurality of harmonically related currents in oscillators coupled so as to force them to op crate in exact harmonic relation, signaling on these respective currents and transmitting them to the receiving end, applying oneoi the received harmonic currents to a corresponding oscillator of a system of oscillators corresponding to those at-the sending end and thereby generating at the receiving end a set of corresponding currents to be utilized for detecting the received signals;

4:. In a signaling system, a plurality of vacuum tube oscillators at thesencling end tuned approximately to frequencies in harmonic relation, a similar set of oscillators at the receivingend, means coupling the oscillators at each end to force them to operate in precise harmonic relation, and means to transmit the current of one oscillator from the sending end and apply it to the correresponding oscillator at the receiving end whereby these oscillators will operate in exact synchronism and all the others will be brought in synchronism, each to each, at the receiving and sending ends,

5. The method of forcing a plurality of vacuum tube oscillators to operate in precise'harmonic relation to a certain fundamental, which consists in tuning them approximately to that relation and coupling them so as to force them into that relation.

\ I In testimony whereof, I have signed my name'to this specification this,19th day of ANDREW- L.

May, 1927 

